The present invention addresses problems related to the insertion of an intraocular lens through a small incision in the human eye.
Reference is made to Applicant""s related application Ser. No. 08/751,181, wherein are illustrated and described certain relevant features and components, which application is incorporated herein by reference.
In recent years, foldable intraocular lenses have largely replaced hard, rigid lenses, the foldable lens being insertable through an incision of approximately xc2xd the size of an incision required for rigid lenses. A small incision enables more rapid recovery, less discomfort for a patient, and avoids many of the possible adverse complications of cataract surgery. Further, the procedure requires less time because suturing is not required.
The problems addressed include undesirable rotation of a folded, compressed lens during passage through a lumen or tubular passage, the maintaining of the correct orientation of a lens relative to an insertion instrument, sudden expansion of unfolding of a compressed lens as it exits the insertion instrument into the eye, and difficulty in insertion of a tip of an insertion instrument into a small incision in the eye of a patient.
Although various folding forceps have been provided for folding flexible lenses, it has generally been preferred by surgeons to utilize insertion devices whereby a lens enters the eye through a tube. Folding forcep devices generally comprise two components in addition to a lens, thus requiring two hands for their utilization.
The improvements according to the invention include a plunger with stabilizing components thereon to exert forces on a folded lens to maintain the lens in folded configuration and to prevent rotation of the lens relative to a lumen wall.
One or more slits in the nozzle end portion enable the spreading of the end portion by passage therethrough of the folded lens after insertion in the eye of a patient, thus to provide ease of admission of the folded lens into the eye of a patient.
Ridges extend longitudinally of the lumen wall to aid in prevention of rotation of a folded lens relative to the lumen wall, these including ridges extending along opposite edges of at least one slit in the nozzle end portion of the insertion instrument to aid in the prevention of rotation of a folded lens relative to the lumen wall.